Low Hips
Marty is a smart guy. However, Lower Hips for the majority of lifters is contraindicated in either the Conventional or Sumo Deadlift.
Higher Hip Position
A Higher Hip Position is more effective.
A Higher Hip Position simulates a Quarter Squat. You can Quarter Squat more than you can Parallel Squat.
Some Deadlifters may drop down into a lower position, prior to driving the weight off the floor, then drive up, engaging the load in the Higher Hip/Quarter Squat Position.
The lifter may appear to be starting with a Lower Hip drive but that isn't the case.
The engagement/contraction in driving the weight off floor is actually in the Higher Hip Position.
Conventional Deadlifts
There are two different types of Conventional Deadlfts
1) Olympic Squat Style Deadlifts
In this movement, the focus is on positioning the bar correctly for the Second Pull.
This requires the back maintains a netural spine position to optomize the Second Pull.
The position for the Second Pull require that the Legs drive the weight off the floor, ensuring a more neutral spine.
The Olympic Squat Deadlift is more like Leg Pressing the weight off the floor to the knees.
2) Powerlifting Back DeadliftIng
Research by Dr Tom McLaughlin (PhD Exercise Biomechanics, former Powerlifter) determined that the Muscle Firing Sequence is...
Back > Legs > Back
The back breaks the weight off the floor with some assistance from the Legs (Quads).
It is a "Bang-Bang" Sequence with the back inititating the drive and then the legs kicking in to assist.
McLaughlin's Research
Nutrition & Health OnLine Magazine
www.nhomag.com
This is an excellent article by Davey Dunn that breaks down McLaughlin's Biomechanical Research on the Conventional Powerlifting and Sumo Deadlift. It is based on McLaughlin's article published in Powerlifting USA, years ago, on the Biomechanics of the Powerlifts. I have those articles. ("Biomechancis Of Powerlifting--
The Deadlift," Dr Tom McLaughlin-Director/Biomechanics Labratory/Auburn University/PLUSA 7/81)
The "Three Distinct Phases of Muscle Involvement" in the Conventional Powerlifting Deadlift
1)
"...The initial drive is done primarily by the back (erector spinae) and not the legs."
"...Research done by Dr. Tom McLaughlin.1
McLaughlin compared the deadlift styles of top powerlifters at the time such as Jon Kuc, Bill Kazmaier, and Vince Anello. His results showed that
all the lifters had similar styles exhibiting back extension at the beginning of the lift. McLaughlin felt that the reason for this is because the total force of the legs is inadequate at the start of the deadlift for most individuals.:
2) "The second distinct phase of the deadlift begins shortly after the bar breaks the floor."
"
As the initial pull from the back begins to lessen, the legs begin to take over. Knee extension and hip extension account for most of the movement until the bar reaches the knees. The primary muscles involved in this phase are the gluteals and hamstrings in hip extension and the quadriceps in knee extension."
3) "The third and final phase is the lockout."
"As the bar passes the knees, the effect of the legs decreases and the lower back again becomes the primary force."
"I was talking to Lamar Gant this week here at Auburn, and he said that he felt years ago his leg drive was strong off the floor, but in recent years he felt his back pulling more at the start. This is probably a reason for the recent craze over stiff-leg deadlifts. They simply develop more back strength for the starting position." ("Biomechancis Of Powerlifting--
The Deadlift," Dr Tom McLaughlin-Director/Biomechanics Labratory/Auburn University/PLUSA 7/81)
Olympic Squat Deadlift Examples
1) Steve Freides
Steve successfully uses this style. As I remember, Steve had some type of back injury year ago.
That may be why his Deadlift technique is perform with an Olympic Squat Deadlift, driving the weight off the floor with his Legs.
However, maybe this is a more natural movement for Steve, where he is stonger.
Anna C
Anna's performs an Olympic Squat Deadlift.
Commonality
1) Conventional Powerlifting Deadlifter
Most of these lifter who breaking the weight off the floor with the Back > Leg > Back method, blow the weight off the floor.
The Sticking Point for these Powerlifter is in the knee area. That based on anedcotal data and supported by research; "Kinematic Analysis of the Powerlifting Style Squat and the Conventional Deadlift During Competition", Journal of Strength and Conditioning Research:
December 2009 - Volume 23 - Issue 9 - p 2574-2580
2I Olympic Squat Style Deadlifters
Using the Legs to drive the weight off the floor, is a slow, tedious process.
Steve and Anna's post of their Olympic Squat Style Deadlifts demonstrate this.
However, once the Bar reaches around the knee area, Steve and Anna's Power dramatically increases.
Anna performs a lot of Olympic Movements. Thus, the Olympic Squat Style Deadlift is the most effective for that.
However, from viewing Anna's Leg Strength in her Olympic Squat Style Deadlifts, my observation is that she'd drive more weight with a Sumo Deadlift.
Caveats of The Conventional Powerlifting Deadlift
One of the interesting caveats of the Conventional Powerlifting Deadlift is the Upper Back Rounding during the "Pull".
Anecotdal data demonstrate that many Conventional Powerlifting Deadlifter have some Upper Back Rounding.
Upper Back Rounding isn't a issue. Lower Back Rounding is a huge issue.
Reaserch by Dr Bret Contreras, determined that Upper Back Rounding enabled lifter to keep the bar closer to the Body's Center of Gravity; decreasing the Torque.
Research by McLaughlin, noted in Davy Dunn's article...
"The studies show that for every inch the bar swings out during the lift the effective load is actually increased 25 percent."
400 lb Deadlift Torque Example
That means, if a lifter allowed the bar to drift an inch farther away from the Body's Center of Gravity. essentially the Bar Load would increase to 500 lbs. A lifter would need to exert over 500 lbs of Force to pull up a 400 lb Deadlift!
To reiterate, Upper Back Rounding ensures a Conventional Powerlifting Deadlifter is able to keep the bar in closer to the Body Center of Gravity. Most Conventional Powerlift Deadlifters do it without thinking about it.